Pencil lead sharpeners



E. C'. PRATT PENCIL LEAD SHARPENERS Oct. 28, 1958 Filed Oct. 12, 1954 R.m T WT mm P C. D N U M D E ATTORNEYS United States Patent C PENCIL LEADSHARPENERS Edmund C. Pratt, Fullerton, Calif.

Application October 12, 1954, Serial No. 461,830

7 Claims. (Cl. 1Z0-91) This invention relates to lead pointer or pencilsharpeners used by draftsmen, architects, photo retouchers and otherswho employ long leads of varying degrees of hardness in mechanicalpencils. However the device can be used to point the lead in the oldertype of wood pencil if the wood is cleared away exposing three-quartersof an inch to one inch of lead.

`An object of the invention is to produce an efficient device to sharpenthe lead in pencils that is rapid in operation, simple in constructionand which will produce a variety of types of lead points withoutadjustment.

Another object is to produce a device to point the leads of a pencil ina choice of three lengths, blunt,

medium and needle, but with all of these points neatly centered andtrue.

Another object is to provide means to remove the surplus graphiteparticles which adhere to the lead of a freshly-pointed pencil and whichare customarily wiped olf on a rag.

Another object is to provide a table of decimal equivalents or otherneeded data, mounted on the device so that the user can revolve the topof same to bring the chosen data to the foreground for easy reading.

Other objects and advantages of the invention will be apparent from astudy of the following specification and drawings.

` Although, in common with many present-day pencil Sharpeners, thisinvention utilizes the surface of abrasive cloth or paper to make thepoints on the leads, the instant device employs a cylinder of abrasiverather than some come-shape or other shaped part which must befabricated by more expensive means. The abrasive cylinders or bands hereused can be fabricated in abrasive-covered cloth or paper in longlengths or tubes and then cut to size and notched, resulting in lessexpensive replacement parts for the user.

Referring to the drawings, which illustrates a preferred embodyment ofthe invention:

Figure l is a perspective view of a device embodying the invention.

Figure 2 is a vertical sectional view of the device, Figure 1.

Referring to Figure 2, the numeral 10 denotes a rocker cup of metal orother suitable material loosely fitting about stud 12 so it can wobblethereon. This is urged upward by spring 11 against a land on thecylindrical stud 12. l

`Cup 10 has mounted thereon the abrasive sleeve 13 which is forceddownwards on the cup until it engages means such as the land 14 engaginga notch in the sleeve to prevent rotation thereof. Cup 10 is preventedfrom rotation about the stud by pin 15 which is pressed into base 16 andextends upward through the bottom of cup 10 through an oversize hole 10aso as not to prevent the cup from wobbling or tipping in any directionwhen urged sidewise by the lead in a pencil inserted through holes 17 inthe nozzles 18.

:Numeral 19 denotes a guide' washerwith a slanting ffice edge tted intothe top of cup 10 to guide the blunt end of a broken lead down over theupper edge of the abrasive cylinder 13.

Spring 11 is loosely set into -a circularl recess 20 in base 16 andurges cup 10 upwards to the land on stud 12, but in operation, permitsthe rocker cup to deviate from its normal position in any direction asurged by the lead in a pencil inserted through any of the nozzles 18.

The numeral 21 denotes a revolving cap into which is cast or pressedthree or more nozzles, such as 18, which are spaced in a circle on thetop of cap 21, but at different distances from the center thereof. Thesenozzles are mounted or cast into the top of cap 21 at different angles,so that when a pencil is inserted into any one of them with the leadextended to go through a hole 17, the angle at which the lead engagesabrasive cylinder 13 is different by a few degrees from what it would bein any other nozzle. This causes the pencil lead to rock the rocker cup10 degrees more or less from its normal position.

It is the combination of the two angles which thus produces on theextended lead of the pencil various lengths of points, and which is animportant feature of the invention and enables different points to beproduced without adjustment of the device.

By reference to Figure 2, it will be seen how the angle of the nozzle 18on the right and its less distance from the center of cap 21 causes,when a lead is inserted through hole 17 therein, the rocker cup 10 .totip more and produce a greater angle with the lead and thus produce ashorter, more blunt point than when the same pencil and lead areinserted through the left nozzle.

Cap 21 revolves on a bearing 22 formed by stud 12, which is pressed intobase 16, and is also threaded at its upper end at 23 to receive thesimilarly threaded bottom of pot 24.

The pot 24 is used for two purposes: first it acts as a retainer nut tohold cap 21 in position so it can revolve about stud 12, secondly pot 12forms a container for the nest of chain woven plastic 25 or some othersuitable material used to clean theloose graphite particles off afreshly sharpened lead.

Such chain woven plastic is in common use and is made from severalplastic materials such as polyethylene. Here it is put to a new use forwhich it has not been previously employed. The chain is composed ofsmall links of rectangular material so that the links have sharp edgeswhich engage and remove the loose graphite particles.

The plastic nest 25 is retained by top 26 which has a hole 27 in itscenter of sufficient size to permit the user to insert the lead of afreshly sharpened lead into it to clean its surface before using it todraw with.

On the skirt of cap 21 is mounted a band of paper, metal foil or othermaterial bearing a printed chart containing data useful to the user,such as decimal equivalents. This chart band 28 can be revolved by theuser until the section of the chart bearing the particular data desiredis in front where it may easily be seen and read.

Base 16 is preferably cast in iron or die-cast in zinc or brass so itwill be fairly heavy and the bottom of it should be covered withskid-proof rubber 30 so that in operation the user will not be forced ortempted to hold the device with one hand while rotating the cap 21 withhis pencil.

The cylindrical apertures in nozzles 18 are drilled or cast of aninternal diameter just sufficient' to hold any of many types ofmechanical pencils or lead pencils, while the holes 17 are drilled orcast a few thousandths larger in diameter than the usual leads sold toarchitects, draftsmen and photo retouchers and others, which leads varyin4 diameter plus or minus four thousandths from a mean. I

of .075. Experimenting has proved that the sizes of the holes in nozles18 and holes 17 are not too critical.

It is almost impossible to break a lead while sharpening a'pencil in thedevice just described, as the user cannot exert enough sideways pressure.to offset the resilience of the rocker cup lt on its spring 11.lnpractical use, the user may as often insert a partially sharpenedlead, thepoint of which has slightly worn dullby vuse in drawing orretouching, as inserting a`blunted broken lead withnopoint as yet onit-at all. ln either event the pressure of the lead as it is guided overguide washer 19 to contact the abrasive cylinder 13 can not only tip therocker cup 1d from its normally centered position as urged by spring 11,Vbut the entire assembly of rocker cup 10, guide washer =19 and abrasive.cylinder 13 can give away downwards upon the urging of the lead in thepencil, yet exert enough gentle pressure on the .lead to sharpen it to atrue-centered point in a vfew revolutions of cap 21.

In use, the device is placed upon a table or drafting board or othersurface, the pencil `or mechanical pencil holder with itsleadrprotruding about three-quarters .of an inch is inserted in thechosen nozzle l (depending upon the length point desired)and, holdingthe .pencil between the lingers, the cap 21 of the device is revolvedseveral times, either clockwise or counter-clockwise until, by removingthe pencil and examining it, the conical point is finished to thesatisfaction of the user. Itis possible, by this method to satisfy thosewho want an almosty sharpened point but who prefer not to .have thepoint a needle-like tip.

All particles of graphite which are ground off on `the abrasive sleeve.13 drop .into .the recess 29`in `the base 1.6 where they accumulate;and the device is operable Veven after the recess is more than half fullof accumulated powdered graphite.

When the surface of the abrasive sleeve 13 has become worn to the pointwhere too many revolutions of cap 21 are required to produce a sharppoint quickly, it is vonly necessary to unscrew the pot 2d to releaserevolving cap 21, reach in and remove the guide washer 19 and take ofithe wo-rn out sleeve, replacing it-with a new one.

The chain-woven mesh of plastic '25 which the user uti lizes to take odthe smudge-making graphite particles from his newly-sharpened lead,permits the particles to drop to the botto-rn of pot 2d because of theslick "urface of the plastic. Thus many months of graphite dustaccumulation in the pot do not prevent continued use of the plastic 25,the top layer of which will function for along time.

AIt is to be understood that the above description of the invention ismerely illustrative and not limitative, as many changes can be madetherein, the invention being as defined by the appendedclaims.

lt will also be noted that the sleeves l are salable as a replacementpart separately Afrom the unit device and are therefore claimed as aseparate invention for use in devices of the classdescribed. Y

The complete cup 1d with sleeve 13 and guide washer 19 is also salableseparately as `a replacement .part and is so claimed as well as thechain woven plastic ZS which comprises a new method of removing theloose graphite particles when employed .in a device of the characterdescribed and may be used for the described purpose in any .suitableholder with other types of Sharpeners.

What `is claimed is:

l. .A pencil lead gpointer including a base having anupstanding annularange; a stud mounted in said base Vand extending 'upwardly .above-saidilange and having spaced shoulders fr umed thereon. facing upwardly and'sube stantiallyQtl" with respect tothe of the stud and the otherVfacing downwardly and having its surface inclined relative to saidaxis; a rocker cup supportcdon said stud in a vnon-rolati-ve Vstate, yetfree to wobble thcreabout; spring means `urging an opening `in the baseof said cup against said shoulder; abrasive material carried by saidcup; a revolvable cap mounted on said stud and having la skirt portionextending downwardly and overlying said flange on said base; and aplurality of sockets carried by said cap, each having a bore spaced at adifferent radial distance from the axis of said cap, and each of saidbores being at a diiferent angle to the normal axis of said cup and at adifferent angle from any other bore.

2. In a pencil lead pointer, a Vbase having a circular cavity therein, astud mounted in said base and having its axis coinciding with -the axis`,of said cavity, a first shoulder formed on said stud disposedsubstantially relative to the axis of said stud and facing upwardly, asecond shoulder formed onsaid stud and inclined to the axis thereof andfacing downwardly, a cup embracing said stud and bearing against saidsecond shoulder and consequently having its axis eccentric to said firstmentioned axes, spring means urging said cup upwardly against saidsecond shoulder, means keying .said cup against rotation, `an abradantcarried on the outer surface of vsaid cup, said spring means comprisinga comparatively light spring -acting against said cup and causing ittoitend to resist angular displacement, va .cap forming a closure forsaid cavity and having a vhub journaled on .said stud inrcontact w-ithsaid first shoulder, 'a socket formed in saidcap to accommodate a pencillead holder, said 'socket having `its .axis so related to the axis of4said stud that a lpencil lead carried by .said holder angularlydisplaces said cup and is pointed at a predeterminedangle 4as said capis rotated.

3. In apencil lead pointer, a base having -a circular cavity therein, astud mounted in said base and having its axis coinciding with the axisof saidcavity, said stud having upper and lower kshaft portions with yanintermediate portion of larger diameter'for providing -opposedshoulders, one facing upwardly and one facing downwardly, `a cupembracing said stud and having a closureiwall with a hole thereinbearing on the lower of said shaft portions, spring means between saidwall and the bottom of said cavity urging said wall into contact withsaid last shoulder, means `keying said cupagainst rotation, an abradantcarried on :the `outer surface of said cup, said spring means actingagainst said cup and causing it to tend to resist angular displacement,a cap forming a closurefor said cavity and having a hub journaled on theupper shaft portion of .said stud, and a socket formed in saidcap toaccommodate a pencil lead holder, said socket having its Vairis inclinedrelative to the axis of said stud so .that a sharp point is formed on apencil `lead carried by said holder .as said cap is rotated.

4. ln .a ,pencil lead pointer, a base having a circular cavity therein,a vertical stud rigidly carried in said base, said stud having upper andlower shaft portions with shoulder means therebetween, said means havingupwardly and downwardly :facing shoulders and saiddow-nwarly facingshoulder having its face inclined -at lan angle greater than 90 relativeto the axis of said stud, a cup embracing said study and havinga wall.portion with a hole therein bearing on said lower shaft portion, meansin said base keying .said `cup against rotation, -an abradant carried onthe outer surface of said cup, a .comparatively light spring vactingupwardly againstsaid cup, holding the wall .portion thercofagainst saidkdownwardly facing shoulder and causing said cup to tend to resistangular displacement, 4a cap forming a closure for` said cavity andhaving a hub journaled on said upper shaft portion .and bearing againstsaid upwardly vfacing shoul-` der, a plurality of sockets `formed insaid cap to Laccommodatepencil lead holders, said sockets having 'their.axes forming diiferentangles with the axis of -said stud, Vso that apencil lead ycarried by said holder positioned in-any'one of said:sockets Adisplaces said cup and is pointed at a differentfanglethereby, than :is produced with the :holder in either of the othersockets, as said cap is rotated.

5. in a pencil lead pointer, a base havinga circular well formedtherein, a vertical stud in said well and rigidly mounted in said base,said stud having upper and lower shaft portions with upwardly anddownwardly facing shoulders therebetween, the second shoulder beingadjacent to the lower shaft portion having its surface inclined at anangle of less than 90 with respect to the axis of said stud, a cupembracing said stud and having a bottom wall with a hole therein bearingon said lower shaft portion, spring means urging said bottom wallagainst said last mentioned shoulder, means keying said cup againstrotation, an abradant carried on the outer surface of said cup, a cap'forming a closure for said cavity and having a hub journaled on saidstud with its lower end in contact with said upwardly facing shoulder, aplurality of sockets formed in said cap each adapted to accommodate apencil lead holder, said sockets having their axes forming differentangles relative to the axis of said stud so that a pencil lead carriedby said holder positioned in either of said sockets may be selectivelypointed sharp, medium, or blunt as said cap is rotated.

6. ln a pencil lead pointer, a base having a circular Well formedtherein, a vertical stud in said well and rigidly mounted in said base,said stud having upper and lower shaft portions with upwardly anddownwardly facing shoulders therebetween, the shoulder adjacent to thelower shaft portion having its surface disposed at an angle of less than90 with respect to the axis of said stud, a cup embracing said stud andhaving a bottom wall with a hole therein bearing on said lower shaftportion, spring means urging said bottom wall against said lastmentioned shoulder, means keying said cup against rotation, an abradantcarried on the outer surface of said cup, a cap forming a closure forsaid cavity and having a hub journaled on said stud and having its lowerend in contact with said upwardly facing shoulder, a plurality ofsockets formed in said cap each adapted to accommodate a pencil leadholder, said sockets having their bases different radial distances outfrom the axis of said stud and angularly disposed so that a pencil leadcarried by said holder may be positioned in either socket in accordancewith whither a sharp point, a medium point, or a blunt point is desired,and the selected point is obtained when said cap is rotated.

7. A pencil pointer including a base, a stud mounted in said base andhaving a shoulder thereon facing upwardly and having an inclinedshoulder facing downwardly, a tiltable rocker cup supported on said studand normally inclined due to contact with said inclined shoulder, springmeans extending between said base and said cup and urging the cupupwardly against said inclined shoulder, keying means extending betweensaid cup and said base to prevent the cup from rotating on said studwhile permitting said cup to wobble about the axis of said stud,abrasive means carried on the external periphery of said cup andoverlying the outer surface thereof, and a revolvable cap mounted onsaid stud above said 90 shoulder, said cap having a plurality of pencilreceiving openings therein having their axes angular with respect to theaxis of said stud with such angle in each case being different from theothers, each of said openings being adapted to receive a pencil andguide the lead thereof into engagement with said abrasive means at aparticular angle thereto which is different from the angle occasioned byany other opening.

References Cited in the file of this patent UNITED STATES PATENTS843,999 Cary Feb. 12, 1907 1,124,436 Hoey Ian. 12, 1915 1,442,867 Engleet al. Jan. 23, 1923 2,540,320 Cayo Feb. 6, 1951 2,613,645 VonKameniczky Oct. 15, 1952 FOREIGN PATENTS 745,309 France Feb. 14, 1923270,866 Switzerland Sept. 30, 1950 808,424 Germany July 31, 1951

